Update flask

@@ -30,7 +30,7 @@ function activate()
 function detect_face(img)
 {
 	let canvas = document.createElement('canvas');
-	let ctx = canvas.getContext("2d")
+	let ctx = canvas.getContext('2d')
 	ctx.src = img;	
 	let src = cv.imread(canvas);
 	let dst = new cv.Mat(src.cols, src.rows, cv.CV_8UC4);
@@ -55,6 +55,8 @@ function detect_face(img)
         let cropped = src.roi(rect);
         cv.imshow(tempCanvas,cropped);
 	}
+	let preview = document.getElementById('preview');
+	cv.imshow(preview, dst);
 	if (faces.size() == 1)
 	{
 		let sender = document.getElementById("sender");
@@ -68,7 +70,6 @@ function detect_face(img)
 	{
 		alert('하나의 얼굴만 등록해주세요.')
 	}
-	cv.imshow('preview', dst);
 }
 
 function submit()